Hydraulic pumps connected to electric motors are used in a variety of applications and industries to pressurize liquids for delivery. Typically, liquid enters the hydraulic pump, the liquid is pressurized by rotating components of the hydraulic pump, and the fluid exits the hydraulic pump for dispensing at a remote location. Depending on the type of hydraulic pump used for a particular application, the rotating components of the hydraulic pump are held in close clearance relative to the surrounding static components.
Electric motors may be connected to hydraulic pumps using rigid drive shafts. The rigid drive shafts transmit torque from the electric motors to the hydraulic pumps. However, if the drive shafts are misaligned from the input shafts of the hydraulic pumps, the misalignment may transmit unwanted force to the hydraulic pumps and may cause wear and premature failure of the internal components of the hydraulic pumps. Further, rigid drive shafts also transmit force to the hydraulic pumps due to axial float of the motors. Accordingly, flexible shaft assemblies that transmit torque from electric motors to hydraulic pumps and limit unwanted forces are required.